The Pokémon Mansion has four floors. The first floor is the entrance to the Pokémon Mansion. In order to get to the other three floors, the player must use Mewtwo statues (which are secret switches) to proceed to each floor, depending on which Mewtwo statue the player uses.

Within the Pokémon Mansion's wreckage, there are books that give valuable information about Mew and Mewtwo, showing that the mansion was the place Mewtwo was created and the place that Mewtwo destroyed, as seen in Pokémon the First Movie - Mewtwo Strikes Back.